from Section 1 - Physiological MR techniques
Published online by Cambridge University Press: 05 March 2013
Introduction
T1-weighted dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) is an experimental technique designed to measure tissue hemodynamic parameters.[1–3] For this purpose, contrast medium (the tracer) is rapidly injected intravenously. The passage of the bolus through the tissue causes changes in the longitudinal relaxation rate R1 (1/T1) that are measured with a dynamic T1-weighted imaging technique (Fig. 9.1). The principles of MRI signal theory are used to determine tracer concentration–time curves from the measured signal changes. In a second step, tracer kinetic principles [4,5] are applied to derive the relevant perfusion and/or blood–brain barrier (BBB) permeability parameters.
Perfusion and permeability parameters
Perfusion parameters characterize the state of the microvasculature (Fig. 9.2). Cerebral blood flow (CBF) quantifies tissue perfusion and is conventionally expressed in units of milliliters of blood per minute per 100 g tissue. Cerebral blood volume (CBV) quantifies the volume of the microvasculature and has the units of milliliters of blood per 100 g tissue. Compared with other organs, normal brain tissue is characterized by low blood volumes, with CBV in the range 2–4 ml/100 g.[6]
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.